Modular broadcast receiver system and method

ABSTRACT

The construction of a receiving apparatus for receiving a broadcast from a plurality of broadcasting providers is simplified. In a receiving apparatus for receiving a broadcast from a plurality of broadcasting providers, of the function blocks which constitute the receiving apparatus, a block used in common irrespective of the broadcasting provider is formed as a common block, and a block different from one broadcasting provider to another is formed as an independent block. These blocks are connected to each other through an IEEE1394 interface, and the common block is shared among the plurality of blocks which are not used in common, so that a receiving process is performed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/799,773 filed May 3, 2007, which is a continuation of U.S.application Ser. No. 10/170,111, filed on Jun. 12, 2002, which is acontinuation of U.S. application Ser. No. 09/162,037, filed on Sep. 28,1998, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an information processing apparatus, aninformation processing method, and a transmission medium and, moreparticularly, to an information processing apparatus which receives adigital broadcast transmitted from a plurality of broadcasting providersand reproduces this digital broadcast, an information processing method,and a transmission medium.

With the advances in image and sound compression technology, etc.,digital broadcasts are being realized.

Conventional digital broadcast receiving apparatuses respond to onlybroadcasting signals from a specific broadcasting provider. Therefore,when a broadcast from a plurality of broadcasting providers is to bereceived, there is a problem in that a plurality of receivingapparatuses are required, making the financial burden on a userconsequently large.

Also, in order to employ a receiving apparatus, an appropriate amount ofspace is required. Therefore, when a broadcast from a plurality ofbroadcasting providers is to be received, there is also a problem infinding the necessary space for multiple receiving apparatus.

SUMMARY OF THE INVENTION

An object of the present invention, which has been achieved in view ofthe above circumstances, is to receive broadcasts from a plurality ofbroadcasting providers by using a simplified apparatus.

To achieve the above-mentioned object, according to a first aspect ofthe present invention, there is provided a digital television signalreceiving system, including a receiver, including a tuner for receivinga scrambled digital television signal, a demodulator for demodulatingthe received scrambled digital television signal, and an interface foroutputting the demodulated scrambled digital television signal; and amodule attachable to the receiver, including a descrambler for inputtingthe demodulated scrambled digital television signal, and an encryptorfor encrypting the descrambled digital television signal and foroutputting the encrypted digital television signal to the interface. Thereceiver further includes a decryptor for decrypting the encrypteddigital television signal received from the module through theinterface; a demultiplexer for receiving and demultiplexing thedecrypted descrambled digital television signal; and a decoder fordecoding the demultiplexed digital television signal.

According to a second aspect of the present invention, there is provideda digital television signal receiver, including a tuner for receiving ascrambled digital television signal; a demodulator for demodulating thereceived scrambled digital television signal; an interface foroutputting the demodulated scrambled digital television signal to adescrambling module attachable to the receiver and for inputting anencrypted descrambled digital television signal from the descramblingmodule; a decryptor for decrypting the encrypted descrambled digitaltelevision signal; a demultiplexer for demultiplexing the decrypteddescrambled digital television signal; and a decoder for decoding thedemultiplexed digital television signal.

According to a third aspect of the present invention, there is provideda descrambling module attachable to a digital television signalreceiver, the descrambling module including an interface for inputting ascrambled digital television signal from the receiver; a descrambler fordescrambling the inputted scrambled digital television signal; and anencryptor for encrypting the descrambled digital television signal andfor outputting the encrypted descrambled digital television signal tothe receiver through the interface; wherein the interface is configuredto input data packets extracted by the receiver and relating to a singleprogram, and the descrambler descrambles the inputted data packets.

According to a fourth aspect of the present invention, there is provideda method of descrambling digital television signals, including receivinga scrambled digital television signal by a receiver; demodulating thereceived scrambled digital television signal; outputting the demodulatedscrambled digital television signal to a descrambling module attachableto the receiver; descrambling the scrambled digital television signal bythe module; encrypting the descrambled digital television signal by themodule; outputting the encrypted digital television signal to thereceiver; decrypting the encrypted television signal received from themodule by the receiver; demultiplexing the decrypted digital televisionsignal; and decoding the demultiplexed digital television signal.

The above and further objects, aspects and novel features of theinvention will become more apparent from the following detaileddescription when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF TEE DRAWINGS

FIG. 1 is a block diagram showing an example of the construction of anembodiment of the present invention.

FIG. 2 is a block diagram showing a detailed example of the constructionof a CI-STB 1 shown in FIG. 1,

FIG. 3 is a block diagram showing a detailed example of the constructionof a CI-Module 2 shown in FIG. 1.

FIG. 4 is a block diagram showing a detailed example of the constructionof a Cl-Storage 3 shown in FIG. 1.

FIG. 5 is a block diagram showing another example of the construction ofthe CI-STB 1.

FIG. 6 is a block diagram showing an example of the construction of aCI-STB 1 a.

FIG. 7 is a block diagram showing an example of the construction of aCI-Post_STB 1 b.

FIG. 8 is a block diagram showing another example of the construction ofthe CI-Post_STB 1 b.

FIG. 9 is a block diagram showing another example of the construction ofthe CI-Module 2 shown in FIG. 1.

FIG. 10 is a block diagram showing still another example of theconstruction of the CI-Module 2 shown in FIG. 1.

FIG. 11 is a block diagram showing yet still another example of theconstruction of the CI-Module 2 shown in FIG. 1.

FIG. 12 is a block diagram showing another example of the constructionof the CI-STB 1 shown in FIG. 1.

FIG. 13 is a block diagram showing another example of the constructionof the CI-Storage 3 shown in FIG. 1.

FIG. 14 is a flowchart illustrating an example of the process performedby the CI-Module 2 shown in FIG. 11.

FIG. 15 is a block diagram showing a detailed example of theconstruction of a CI-Modem 4.

FIG. 16 is a block diagram showing a detailed example of theconstruction of a CI-Card 5.

FIG. 17 is a block diagram showing another example of the constructionof the CI-Post_STB 1 b.

FIG. 18 is a flowchart illustrating an example of a process performed inthe embodiment of FIG. 17.

FIG. 19 is a block diagram showing another example of the constructionof the CI-Module 2 shown in FIG. 1.

DETAILED DESCRIPTION

FIG. 1 is a block diagram showing an example of the construction of anembodiment of an information processing apparatus of the presentinvention.

In this figure, CI-STBs 1-1 and 1-2 receive a broadcasting signal from abroadcasting provider, demodulate it, and then output the demodulateddata stream via an IEEE1394 interface. The demodulated data stream issubjected to a predetermined process by CI-Modules 2-1 to 2-3, and isinput to the CI-STBs 1-1 and 1-2 again, whereby the plurality ofinformation contained in the data stream is separated and then theobtained information is reproduced, respectively.

The CI-Modules 2-1 to 2-3 perform a descrambling process on the datastream output from the CI-STBs 1-1 and 1-2, and output the obtainedstream via the IEEE1394 interface.

Since this descrambling process is unique to each broadcasting provider,each of the CI-Modules 2-1 to 2-3 performs a descrambling process on adata stream from a predetermined broadcasting provider.

A CI-Storage 3 records a data stream output from the CI-STBs 1-1 and 1-2or the CI-Modules 2-1 to 2-3.

FIG. 2 is a block diagram showing a detailed example of the constructionof the CI-STB 1 shown in FIG. 1.

In this figure, a tuner 10 receives an RF (radio frequency) signal froma broadcasting provider and extracts a signal of a predeterminedfrequency. A demodulator 11 demodulates the signal of the predeterminedfrequency extracted by the tuner 10 so as to be converted into a datastream.

A digital interface 12, which is an interface that complies with theIEEE1394 standard, outputs a data stream demodulated by the demodulator11 to an external apparatus and inputs a data stream from an externalapparatus.

A demultiplexer 13 separates a plurality of information which forms adata stream (a data stream on which a descrambling process has beenperformed) input from the external apparatus through the digitalinterface 12, and supplies it to an AV (Audio Video) decoder 14.

The AV decoder 14 decodes each of the plurality of information separatedby the demultiplexer 13. More specifically, the AV decoder 14 decodes,for example, each of the sound information and the image informationseparated by the demultiplexer 13, and outputs the obtained soundsignals and image signals.

An MPU (Microprocessor Unit) 15 controls each section of the apparatusand performs predetermined computation processes as required.

FIG. 3 is a block diagram showing a detailed example of the constructionof the CI-Modules 2-1 to 2-3 shown in FIG. 1.

In this figure, a digital interface 21, which is an interface thatcomplies with the IEEE1394 standard, inputs a data stream output fromthe CI-STBs 1-1 and 1-2 and outputs a data stream on which adescrambling process has been performed by a descrambler 22.

An MPU 23 controls each section of the apparatus, and performs variouscomputations as required.

FIG. 4 is a block diagram showing a detailed example of the constructionof the CI-Storage 3 shown in FIG. 1.

In this figure, a digital interface 31 is an interface that complieswith the IEEE1394 standard in the same manner as in the above-describedcase.

A storage section 32, formed of a semiconductor memory and a magneticrecording medium, stores a data stream output from the digital interface31, and reads a stored data stream and outputs it to the digitalinterface 31, under the control of an MPU 33.

The MPU 33 controls each section of the apparatus and performspredetermined computations as required.

Next, the operation of the above embodiment is described.

It is assumed that a broadcasting signal (RF signal) from a particularbroadcasting provider A is received by the tuner 10 of the CI-STB 1-1.The tuner 10 extracts a signal of a predetermined frequency from thebroadcasting signal and outputs it to the demodulator 11.

The demodulator 11 performs a demodulation process on the broadcastingsignal of the predetermined frequency extracted by the tuner 10 andoutputs the obtained data stream to the digital interface 12.

The digital interface 12 outputs the data stream supplied from thedemodulator 11 as a sequence of packets that comply with the IEEE1394standard. At this time, the data stream is transmitted in an Isochronoustransfer mode suitable for real-time reproduction of images, sound, etc.

The communications among the MPUs of respective apparatus through theIEEE1394 are performed by asynchronous transfer.

The data stream output from the CI-STB 1-1 is supplied, for example, tothe CI-Module 2-1.

The digital interface 21 of the CI-Module 2-1 inputs the data streamoutput from the CI-STB 1-1 and supplies it to the descrambler 22. Thedescrambler 22 performs a descrambling process on the data streamsupplied from the digital interface 21. As a result, the scrambling,which has been performed on the data stream by the broadcasting providerin order to prohibit viewing by someone other than a subscriber, isdescrambled.

The output of the descrambler 22 is supplied to the digital interface 21again. As a result, the digital interface 21 outputs the output of thedescrambler 22 as a sequence of packets that comply with the IEEE1394standard.

The sequence of packets output from the Cl-Module 2-1 are received bythe CI-STB 1-1 again.

The digital interface 12 of the CI-STB 1-1 receives the sequence ofpackets sent from the CI-Module 2-1 and supplies them to thedemultiplexer 13.

The demultiplexer 13 separates the plurality of information contained inthe data stream output from the digital interface 12. For example, inthe case where this data stream is composed of sound data and imagedata, the demultiplexer 13 separates the data stream into the sound dataand the image data and supplies this data to the AV decoder 14.

The AV decoder 14 decodes the information separated by the demultiplexer13 and outputs it. For example, in the case where the data stream iscomposed of sound data and image data, the AV decoder 14 performs adecompression process on each of the sound data and the image data andoutputs the obtained sound signals and image signals.

In the case where predetermined control information is supplied from theMPU 15 or the MPU 23 to the CI-Storage 3 through the IEEE1394 interface,the CI-Storage 3 records the data stream transmitted between the CI-STB1-1 and the CI-Module 2-1. More specifically, the MPU 33 receiving acontrol command instructing that the data stream is to be recordedcontrols the digital interface 31 so that the received data stream issupplied to the storage section 32. As a result, the data stream isstored in the storage section 32.

It is also possible to supply the data stream stored in the storagesection 32 in this manner to the CI-STB 1-1 and the CI-Module 2-1 and toreproduce it.

In the above, a case is described in which a broadcasting signal fromthe broadcasting provider A is received. In the case where abroadcasting signal from a broadcasting provider B is received and adescrambling process corresponding to the broadcasting provider B isperformed by the CI-Module 2-2, for example, a data stream received bythe CI-STB 1-1 is subjected to a descrambling process by the CI-Module2-2, and then is supplied to the CI-STB 1-1 again, whereby the datastream is decoded into the original sound signals and image signals.Also, if it is assumed that the CI-Module 2-3 corresponds to abroadcasting provider C, while the CI-STB 1-1 is receiving the broadcastof the broadcasting provider A by using the CI-Module 2-1, the CI-STB1-2 is able to receive a broadcast of the broadcasting provider B or thebroadcasting provider C by using the CI-Module 2-2 or the CI-Module 2-3.Furthermore, it is also possible for the CI-STB 1-1 and the CI-STB 1-2to receive the data stream which is being output by the CI-Module 2-1 atthe same time.

In the manner described above, since the portions formed of the samecomponents are formed into CI-STBs 1-1 and 1-2 irrespective of thebroadcasting provider and the descrambler 22 requiring a process uniqueto each broadcasting provider is formed into independent components asCI-Modules 2-1 to 2-3, in a case in which broadcasting signals from aplurality of broadcasting providers are received, a common functionblock can be shared, making it possible to view many broadcasts at a lowcost.

FIG. 5 is a block diagram showing another example of the construction ofthe CI-STBs 1-1 and 1-2 shown in FIG. 1. Components in FIG. 5 whichcorrespond to those of FIG. 2 are given the same reference numeral, andaccordingly, a description thereof has been omitted.

In the embodiment of FIG. 5, in comparison with the case of FIG. 2, aPID (Packet ID) filter 100 is newly added. The remaining construction isthe same as in the case of FIG. 2.

The PID filter 100 extracts only a predetermined program from the datastream output from the demodulator 11 and supplies it to the digitalinterface 12.

Next, the operation of the above embodiment is described.

In the case where the sound data and the image data which form thebroadcast received by the tuner 10 have been compressed in accordancewith MPEG (Moving Picture Experts Group), there is a case in which aplurality of programs have been multiplexed on one data stream.

In the case where such a broadcasting signal is received, the PID filter100 extracts only the packet for the desired program from the transportstream output from the demodulator 11 by referring to a PID (Packet IDof MPEG) and then supplies the packet to the digital interface 12. As aresult, since only the packet for the desired program is sent out fromthe digital interface 12, for example, the amount of processing in theCI-Modules 2-1 to 2-3 is reduced, and in the case where the data streamis stored in the CI-Storage 3, it is possible to reduce the requiredstorage capacity.

Although, in the above embodiment, the CI-STBs 1-1 and 1-2 include thePID filter 100, it is possible for the CI-Modules 2-1 to 2-3 to includeit. Also, with such a construction, it is possible to reduce the amountof data transmitted over the IEEE1394 bus.

FIGS. 6 and 7 are block diagrams showing another example of theconstruction of the CI-STBs 1-1 and 1-2 shown in FIG. 1. Components inFIGS. 6 and 7 which correspond to those of FIG. 2 are given the samereference numeral, and accordingly, a description thereof has beenomitted.

In the embodiment of FIGS. 6 and 7, the CI-STBs 1-1 and 1-2 shown inFIG. 2 are divided into two portions. More specifically, the CI-STBs 1-1and 1-2 shown in FIG. 2 are divided into the portion shown in FIG. 6,CI-Pre_STB 1 a, including the tuner 10 and the demodulator 11 and theportion shown in FIG. 7, CI-Post_STB 1 b, including the demultiplexer 13and the AV decoder 14. The respective portions include MPUs 15-1 and15-2 required for control and digital interfaces 12-1 and 12-2 requiredfor exchanging data.

Next, the operation of the above embodiment is described.

The broadcasting signal (RF signal) from the broadcasting provider Areceived by the tuner 10 is received by the tuner 10 of the CI-Pre_STB 1a. The tuner 10 extracts a signal of a predetermined frequency from thebroadcasting signal and outputs it to the demodulator 11.

The demodulator 11 performs a demodulation process on the broadcastingsignal of the predetermined frequency extracted by the tuner 10 andoutputs the obtained data stream to the digital interface 12-1.

The digital interface 12-1 outputs the data stream supplied from thedemodulator 11 as a sequence of packets that comply with the IEEE1394standard.

The data stream output from the digital interface 12-1 is supplied, forexample, to the CI-Module 2-1 whereby it is subjected to a descramblingprocess and is sent out to the IEEE1394 bus again.

The sequence of packets output from the CI-Module 2-1 are received bythe digital interface 12-2 of the CI-Post_STB 1 b. The digital interface12-2 receives the sequence of packets sent out from the CI-Module 2-1and supplies them to the demultiplexer 13.

The demultiplexer 13 separates a plurality of information contained inthe data stream output from the digital interface 12-2 and supplies itto the AV decoder 14. The AV decoder 14 decodes the informationseparated by the demultiplexer 13 and outputs the original image andsound signals.

According to the above embodiment, in the case where a CI-STB is added,only the portion having the required functions can be added, andtherefore, an unwanted expense can be prevented.

FIG. 8 is a block diagram showing another example of the construction ofthe CI-Post_STB 1 b shown in FIG. 7. Components in FIG. 8 whichcorrespond to those of FIG. 7 are given the same reference numeral, andaccordingly, a description thereof has been omitted.

In the embodiment of FIG. 8, in comparison with the case of FIG. 7, aspeaker 111 and a CRT monitor 112 are added. The remaining constructionis the same as in the case of FIG. 7.

The speaker 111 converts a sound signal output from the AV decoder 14into sound. Also, the CRT monitor 112 displays and outputs image signalsoutput from the AV decoder 14.

Next, the above embodiment is briefly described.

For example, the sequence of packets output from the CI-Module 2-1 arereceived by the digital interface 12-2 of the CI-Post_STB 1 b. Thedigital interface 12-2 receives the sequence of packets sent out fromthe CI-Module 2-1 and supplies them to the demultiplexer 13.

The demultiplexer 13 separates a plurality of information contained inthe data stream output from the digital interface 12-2 and supplies itto the AV decoder 14. The AV decoder 14 decodes the informationseparated by the demultiplexer 13, and outputs the sound signals to thespeaker 111 and outputs the image signals to the CRT monitor 112.

As a result, the image is displayed on the CRT monitor 112, and thecorresponding sound is output from the speaker 111.

According to such an embodiment, the CI-Post_STB 1 b. and the speaker111 and the CRT monitor 112 can be formed into one unit.

Next, referring to FIG. 9, another example of the construction of theCI-Module 2 is described.

FIG. 9 is a block diagram showing another example of the construction ofthe CI-Module 2 shown in FIG. 1. Components in FIG. 9 which correspondto those of FIG. 3 are given the same reference numeral, andaccordingly, a description thereof has been omitted. In this embodiment,a selector 200 is newly added, and also, the descrambler 22 is increasedin number to two descramblers 22-1 and 22-2. The remaining constructionis the same as in the case shown in FIG. 3.

The selector 200 supplies the data stream output from the digitalinterface 21 to either the descrambler 22-1 or the descrambler 22-2,selects either of the data streams output from the descrambler 22-1 andthe descrambler 22-2, and supplies it to the digital interface 21.

The descrambler 22-1 and the descrambler 22-2 perform, for example, adescrambling process corresponding to the broadcasting provider A andthe broadcasting provider B, respectively.

Next, the operation of the above embodiment is described.

For example, it is assumed that the descrambler 22-1 corresponds to thebroadcasting provider A, and the descrambler 22-2 corresponds to thebroadcasting provider B. In such a case, in the case where, for example,a broadcast from the broadcasting provider B is received, the MPU 23controls the selector 200 SO that it selects the descrambler 22-2.

Then, when the data stream corresponding to the broadcasting provider Bis output from the CI-STB 1-1, the digital interface 21 receives thedata stream and outputs it to the selector 200. Since the selector 200is connected to the descrambler 22-2 as described above, the data streamis subjected to a descrambling process by the descrambler 22-2, and thensupplied to the digital interface 21 again through the selector 200.

The data stream output from the digital interface 21 is reproduced bythe CI-STB 1-1.

In the case where a broadcast corresponding to the broadcasting providerA is received, the selector 200 selects the descrambler 22-1.

According to the above embodiment, since the CI-Module 2 includes thedescramblers 22-1 and 22-1 corresponding to different broadcastingproviders, and the selector 200, SO that a desired descrambler isselected by the selector 200 in such a manner as to correspond to thebroadcasting provider of a broadcast to be received, it is possible forone CI-Module 2 to receive broadcasts of a plurality of broadcastingproviders.

Next, referring to FIG. 10, another example of the construction of theCI-Module 2 is described.

FIG. 10 is a block diagram showing another example of the constructionof the CI-Module 2 shown in FIG. 1. Components in FIG. 10 whichcorrespond to those of FIG. 9 are given the same reference numeral, andaccordingly, a description thereof has been omitted. In this embodiment,in comparison with the case of FIG. 9, the selector 200 has beenomitted, and also, the digital interface 21 has been replaced with adigital interface 210. The remaining construction is the same as in thecase shown in FIG. 9.

Next, the operation of the above embodiment is briefly described.

In the embodiment shown in FIG. 10, it is possible for the descrambler22-1 and the descrambler 22-2 to perform a descrambling processsimultaneously on the data streams from two types of broadcastingproviders. Therefore, in the case of FIG. 10, it is possible to receivebroadcasts from two broadcasting providers at the same time.

Next, the above embodiment is briefly described.

For example, it is assumed that the descrambler 22-1 corresponds to thebroadcasting provider A, and the descrambler 22-2 corresponds to thebroadcasting provider B.

Then, when the data stream corresponding to each of the broadcastingproviders A and B is output from the CI-STB 1-1 and the CI-STB 1-2,respectively, the digital interface 210 receives these data streams andsupplies them to the descramblers 22-1 and 22-2, respectively. As aresult, the data streams are subjected to the descrambling process bythe descramblers 22-1 and 22-2 and then are sent out through the digitalinterface 210.

The data streams corresponding to the broadcasting provider A and thebroadcasting provider B output from the digital interface 210 arereproduced simultaneously by the CI-STB 1-1 and the CI-STB 1-2,respectively.

According to the above embodiment, it is possible for one apparatus toreproduce a plurality of broadcasts at the same time.

FIG. 11 is a view showing another example of the construction of theCI-Module 2 shown in FIG. 1. Components in FIG. 11 which correspond tothose of FIG. 3 are given the same reference numeral, and accordingly, adescription thereof has been omitted. In the embodiment of FIG. 11, incomparison with the case of FIG. 3, an encryptor 220, an IC card IF 221,an IC card 222, and a modem section 223 are newly added. The remainingconstruction is the same as in the case of FIG. 3.

The encryptor 220 encrypts a data stream output from the descrambler221.

The IC (Integrated Circuit) card IF (Interface) 221 writes predeterminedinformation into the IC card 222 and reads predetermined informationstored in the IC card 222. The IC card 222 can be inserted into andremoved from the IC card IF 221.

The modem section 223 is connected to the broadcasting provider sidethrough a public network so that information, such as accountinginformation, can be exchanged with the provider.

FIG. 12 is a block diagram showing an example of the construction of theCI-STB 1 corresponding to the CI-Module 2 of FIG. 11. Components in FIG.12 which correspond to those of FIG. 2 are given the same referencenumeral, and accordingly, a description thereof has been omitted.

In the embodiment shown in FIG. 12, in comparison with the case of FIG.2, a decryptor 120 is newly added. The remaining construction is thesame as in the case of FIG. 2.

The decryptor 120 decodes the data stream encrypted by the encryptor 220of FIG. 11 into the original data stream.

Therefore, the data stream output from the CI-Module 2 shown in FIG. 11cannot be reproduced if the CI-STB 1 shown in FIG. 12 is not used.Therefore, according to such a technique as above, only the dulyauthorized apparatus can reproduce information.

FIG. 13 is a block diagram showing an example of the construction of theCI-Storage 3 corresponding to the CI-Module 2 of FIG. 11. Components inFIG. 13 which correspond to those of FIG. 4 are given the same referencenumeral, and accordingly, a description thereof has been omitted.

In this embodiment, a decryptor 300 is newly added. The remainingconstruction is the same as in the case of FIG. 4.

According to such a construction, since it is possible to decode thedata stream encrypted by the encryptor 220 of the CI-Module 2 of FIG. 11and to store the decoded data stream in the storage section 32, only theduly authorized Cl-Storage 3 can store the data stream.

There is a case in which for the protection of the copyright ofinformation transmitted through the IEEE1394 interface, an encryptionfunction and a decoding function are provided within the digitalinterface. In that case, there is no need to provide the above-describedencryptor 220 and decryptors 120 and 300.

Next, referring to FIG. 14, the operation of the above embodiment isdescribed.

FIG. 14 is a flowchart illustrating an example of the process performedin the embodiment of FIGS. 11 to 13. When this process is performed, instep 51, the MPU 23 obtains a viewing program. More specifically, whenthe system is powered on and a desired program is selected by the user,the MPU 23 obtains a packet which is contained in the data stream outputfrom the digital interface 21 and which contains information for theselected program.

In the subsequent step S2, the accounting information is obtained. Morespecifically, the MPU 23 obtains the accounting information of theprogram which is viewed currently by referring to the packet containingthe accounting information from among the packets obtained in step S1.The process then proceeds to step S3.

In step S3, limitation information is obtained. More specifically, theMPU 23 obtains information, such as the limitation number of the outputapparatuses, by referring to the limitation information in the packetcontaining the accounting information referred to in step S2.

In step S4, the MPU 23 detects the number of apparatuses as the objectsof output of data stream output from the descrambler 22 and compares itwith the limitation information obtained in step S3, thereby determiningwhether or not the number of output apparatuses is greater than thelimitation number (step 5). When the result shows that the number ofoutput apparatuses is greater (YES) than the limitation number, theoutput apparatuses corresponding to the limitation number from among theoutput apparatuses as the objects of output are determined (step 6). Forexample, the output apparatus selected earlier is given priority in thesequence in which the user specified as an output apparatus. The dataencrypted by the encryptor 220 is transmitted to only output apparatuseswithin the limitation number, selected in this manner, in isochronouscommunication, and information for decoding the encrypted data istransmitted in asynchronous communication of IEEE1394 (step 7).

Limitation of the number of apparatuses as the objects of output may beperformed for each type of apparatus, for example, in such a manner thatN is a limitation number for model A and M is a limitation number formodel B.

As a result of the comparison in step S5, when it is determined that thenumber of output apparatuses is smaller (NO) than the limitation number,the process proceeds to step S7 where the data encrypted by theencryptor 220 is transmitted in the isochronous communication to onlythe selected output apparatuses within the limitation number, andinformation for decoding the encrypted data is transmitted in theasynchronous communication of IEEE1394 (step 7). In the subsequent stepS8, the MPU 23 computes the account charge. More specifically, the MPU23 computes the sum of the product of the number of CI-Modules 2 whichare the output destinations at present and the account charge f₁ perCI-Module 2, and the product of the number of CI-Storages 3 which arethe output destinations and the account charge f₂ per CI-Storage 3. Thecomputed value is supplied as the account charge to the IC card 222 inwhich it is stored therein in step S9. Then, the process is terminated(END).

According to the above process, the number of apparatuses for theobjects of output can be smaller than the limitation number, andaccounting can be performed according to the type of output apparatusand the number thereof. Therefore, on the broadcasting provider side, itis possible to limit, as required, the use of an apparatus on the userside. Furthermore, for example, by setting the account charge f₂ in thecase where the information is stored in the CI-Storage 3 higher than theaccount charge f₁ in the case where information is viewed by theCI-Module 2, it is possible to perform accounting which is appropriateto the use of the information and to the number of output apparatuses.

As a result of a process such as the above, the account charge stored inthe IC card 222 can be transmitted to the broadcasting provider sidethrough the modem section 223, for example, at an incidence of once perday, and the account charge of each user can be computed.

Furthermore, according to the above embodiment, it is also possible tolimit the number of apparatuses for the objects of output.

In the modem section 223 and the IC card 222 which constitute theCI-Module 2 shown in FIG. 11, there are often cases in which thespecifications differ from one broadcasting provider to another, theviewing history is stored in different data formats, or the method ofpayment of the account charge is different. However, in a case where thesame function block can be used among different broadcasting providers,a certain function block of the CI-Module 2 is, for example, formed asan independent block so that it can be used by another CI-Module 2,thereby making it possible to simplify the construction of the CI-Module2.

FIGS. 15 and 16 show block diagrams of a case in which a function blockwhich can be shared among different broadcasting providers is formed asan independent block.

FIG. 15 shows an example of the construction of a CI-Modem 4 in whichonly a modem section 41 is an independent block. This embodimentcomprises a digital interface 40, a modem section 41, and an MPU 42.

FIG. 16 shows an example of the construction of a CI-Card 5 in whichonly the IC card is formed as an independent block. This embodimentcomprises a digital interface 50, an IC card IF 51, an IC card 52, andan MPU 53.

Each block of the above embodiment is the same as in the above-describedcase, and accordingly, a description thereof has been omitted.

In the manner described above, since a function block which can beshared among a plurality of broadcasting providers is an independentcomponent, it is possible to reduce the cost of the apparatus by anamount corresponding to the shared function blocks.

In digital broadcasts, there are not a few cases in which a charge mustbe paid per program (for example, Pay_Per_View). By performing apredetermined limitation on such a program, for example, it is possibleto prevent a child from freely viewing a pay program. Next, adescription is given of an example of the construction of theCI-Post_STB 1 b which makes such a limitation possible.

FIG. 17 is a view showing an example of the construction of theCI-Post_STB 1 b. Components in FIG. 17 which correspond to those of FIG.7 are given the same reference numeral, and accordingly, a descriptionthereof has been omitted. In this embodiment, in comparison with thecase of FIG. 7, an IC card IF 221, an IC card 222, a speaker 111, and aCRT monitor 112 are newly added. Each block is the same as in theabove-described case, and accordingly, a description thereof has beenomitted.

Next, referring to FIG. 18, the operation of the above embodiment isdescribed.

FIG. 18 is a flowchart illustrating an example of a process performed inthe embodiment shown in FIG. 17.

When this process is performed, in step S20, the MPU 15-2 obtains aviewing program. More specifically, when the system is powered on and adesired program is selected by the user, the MPU 15-2 obtains a packetwhich is contained in the data stream output from the digital interface12-2 and which contains information for the selected program.

In the subsequent step S21, accounting information is obtained. Morespecifically, the MPU 15-2 obtains the accounting information of theprogram which is viewed currently by referring to the packet containingaccounting information from among the packets obtained in step 520. Theprocess then proceeds to step S22.

In step S22, reception limitation information is obtained. Morespecifically, the MPU 15-2 obtains the reception limitation informationfrom the IC card 222 through the IC card IF 221.

In step S23, the MPU 15-2 determines whether or not the program to beviewed can be viewed. More specifically, the MPU 15-2 refers to thereception limitation information obtained in step S22 in order todetermine whether or not the program which is viewed currently is aprogram in which, for example, a child lock is applied. When the resultshows that the program to be viewed is such that a child lock is applied(NO: a program which cannot be viewed), the process is terminated (END).Also, when it is determined that a child lock is not applied (YES: aprogram which can be viewed), the process proceeds to step S24.

In step S24, the MPU 15-2 reads the viewing history from the IC card222, computes a total number of program viewing up to the present time,and compares the total number of program viewing with the upper limit ofnumber of receptions contained in the reception limitation informationobtained in step S22 in order to determine whether or not the number ofprogram viewing is smaller than the upper limit of the number ofreceptions. When the result shows that the number of program viewing isgreater than the upper limit of the number of receptions (NO), theprocess is terminated (END). Also, when it is determined that the numberof receptions is not greater than the upper limit of the number ofreceptions (YES), the process proceeds to step S25.

In step S25, the MPU 15-2 reads the viewing history from the IC card222, computes the total program reception fee up to the present time,and compares the total program reception fee with the upper limit of thereception fee contained in the reception limitation information obtainedin step S22 in order to determine whether or not the program receptionfee is smaller than the upper limit of the reception fee. When theresult shows that the program reception fee is greater than the upperlimit of the reception fee (NO), the process is terminated (END). Also,when it is determined that the reception fee is not greater than theupper limit of the reception fee (YES), the process proceeds to stepS26.

In step S26, the MPU 15-2 reads the present time from a timer section(not shown), and compares the time with the allowable reception timeperiod contained in the reception limitation information obtained instep S22 in order to determine whether or not the present time isincluded in the allowable reception time period. When the result showsthat the present time is not within the allowable reception time period(NO), the process is terminated (END). Also, when it is determined thatthe present time is in the allowable reception time period (YES), theprocess proceeds to step S27.

In step S27, the reproduction of the broadcasting program is started.

According to a process such as the above, in the case where a child lockis applied to the program to be viewed, this lock can be detected tolimit the viewing. Not only in a case in which the total number ofreceptions of programs is greater than the upper limit of the number ofreceptions preset by a user, but also in a case in which the totalreception fee is greater than the upper limit of the reception feepreset by a user, it is possible to limit viewing. Furthermore, in orderto prevent a child from viewing a late-night program, also when thepresent time is not included in the allowable reception time period,viewing can be limited.

Although in the above embodiment the tuner 10 is handled as a commonpart irrespective of the broadcasting providers, in a case in which, forexample, transmission configurations (for example, a satellitebroadcast, a ground-wave program, or a cable broadcast) frombroadcasting providers are different, this tuner section 10 cannot behandled as a common part. In such a case, as shown in FIG. 19, it ispreferable that the tuner 10 be included in the CI-Module 2.

FIG. 19 is a block diagram showing an example of the construction of theCI-Module 2 corresponding to the above-described case. Components inFIG. 19 which correspond to those of FIG. 3 are given the same referencenumeral, and accordingly, a description thereof has been omitted.

In the embodiment of FIG. 19, in comparison with the case of FIG. 3, thetuner 10 and the demodulator 11 are newly added. The remainingconstruction is the same as in the case of FIG. 3.

Since the tuner 10 and the demodulator 11 are described earlier, adescription thereof has been omitted.

Next, the operation of the above embodiment is described.

The RF signal of a predetermined frequency extracted by the tuner 10 isdemodulated by the demodulator 11 and output in the form of a datastream. The descrambler 22 performs a descrambling process on the datastream obtained as a result of demodulation and outputs the obtaineddata stream through the digital interface 21.

The data stream output through the digital interface 21 is input, forexample, to the CI-Post_STB 1 b shown in FIG. 7, whereby a reproductionprocess is performed, and the image signals and the sound signals areoutput.

According to the above embodiment, when the tuner 10 is differentdepending on the broadcasting provider, the function blocks can beshared, and accordingly, the cost of the apparatus can be reduced.

Finally, although in the above embodiment a CI-STB and a CI-Module areused in combination in order to receive a broadcast, in a case in whichreception is possible even if processing is not performed by theCI-Module, it is preferable that processing be performed by only theCI-STB.

For example, in the case where the CI-STB takes the form shown in FIG.2, when an external apparatus connected to the IEEE1394 bus does notrequire a data stream of a broadcast, the digital interface 12 mayoutput the output of the demodulator 11 directly to the demultiplexer 13without outputting it to the outside. According to such a method, theamount of information transmitted on the IEEE1394 bus can be reduced,thereby allowing exchange of information to be smoothly performed amongthe other apparatuses.

In this specification, the examples of the transmission medium includenot only information recording media, such as FDs (floppy disks) orCD-ROMs (compact disc-read-only memories), but also network transmissionmedia, such as the Internet or a digital satellite.

According to the information processing apparatus, the informationprocessing method transmission medium, and the transmission medium ofthe present invention, broadcasting signals are received, the signal ofa predetermined channel is selected from the received broadcastingsignals, the selected signal of the predetermined channel is demodulatedinto a data stream composed of a plurality of information, and thedemodulated data stream is output to an external apparatus through aninterface. Therefore, when broadcasts from a plurality of broadcastingproviders are received, it is possible to reduce the cost of theapparatus by an amount corresponding to the common function blocks.

According to the information processing apparatus, the informationprocessing method, and the transmission medium of the present invention,a data stream processed by an external apparatus is input through aninterface, a plurality of information contained in the input data streamis separated, each of the plurality of separated information is decoded,and the plurality of decoded information is output to a correspondingreproduction apparatus. Therefore, when broadcasts from a plurality ofbroadcasting providers are received, it is possible to reduce the costof the apparatus by an amount corresponding to the common functionblocks.

According to the information processing apparatus, the informationprocessing method, and the transmission medium of the present invention,a data stream processed by an external apparatus is input through aninterface, the input data stream is descrambled, and the descrambleddata stream is output to an external apparatus through an interface.Therefore, it is possible for the same apparatus to receive broadcastsfrom a plurality of broadcasting providers.

According to the information processing apparatus, the informationprocessing method, and the transmission medium of the present invention,a data stream on which a predetermined process is performed by anexternal apparatus and which is then encrypted is input through aninterface, the input encrypted data stream is decoded, and the decodeddata stream is stored. Therefore, it is possible to prevent unauthorizedcopying of information into a storage apparatus which is not dulyauthorized by the broadcasting provider side.

Many different embodiments of the present invention may be constructedwithout departing from the spirit and scope of the present invention. Itshould be understood that the present invention is not limited to thespecific embodiments described in this specification. To the contrary,the present invention is intended to cover various modifications andequivalent arrangements included within the spirit and scope of theinvention as hereafter claimed. The scope of the following claims is tobe accorded the broadest interpretation so as to encompass all suchmodifications, equivalent structures and functions.

1. A content signal receiving system comprising: a receiver, comprisinga first receiving means for receiving a scrambled digital contentsignal; a first interfacing means for outputting said received scrambledcontent signal; a module attachable to said receiver, comprising adescrambler means for inputting demodulated scrambled digital contentsignal; and a first encrypting means for encrypting said descrambleddigital content signal and for outputting said encrypted digital contentsignal to said interface; wherein said receiver further comprises adecrypting means for decrypting said encrypted digital content signalreceived from said module through said interface; a demultiplexing meansfor receiving and demultiplexing said decrypted descrambled digitalcontent signal; and a decoding means for decoding said demulitplexeddigital content signal.
 2. The content receiving system according toclaim 1, further comprising: a storage device comprising, a secondinterfacing means for receiving said encrypted digital content signalfrom said module, a second decrypting means for decrypting said receivedencrypted digital content signal, and a storage means for storing saiddecrypted digital content signal from said second decryptor.
 3. Thecontent receiving system according to claim 1, wherein said receiverfurther comprises a first means for processing, said module furthercomprises a second means for processing, and wherein communicationsbetween said first and second means for processing is in accordance witha protocol that is different from that of communications of said digitalcontent signal between said receiver and module.
 4. The contentreceiving system according to claim 1, wherein said receiver furthercomprises a filtering means for extracting data packets related to asingle program, and wherein said interface means outputs said extracteddata packets to said module.
 5. The content receiving system accordingto claim 4, wherein said receiver further comprises a first means forprocessing means, said module further comprises a second means forprocessing, and communications between said first and second means forprocessing are in accordance with a protocol that is different from thatof communications of said digital content signal between said receiverand said module.
 6. A content signal receiver, comprising: a firstreceiving means for receiving a scrambled digital content signal; afirst interfacing means for outputting said received scrambled contentsignal to a descrambling module attachable to said receiver and forinputting an encrypted descrambled digital content signal from saiddescrambling module; a means for decrypting said encrypted descrambleddigital content signal; a means for demultiplexing said decrypteddescrambled digital content signal; and a means for decoding saiddemultiplexed digital content signal.
 7. The content signal receiveraccording to the claim 6, wherein said receiver further comprises afirst means for processing, said module further comprises a second meansfor processing, and communications between said first and second meansfor processing are in accordance with a protocol that is different fromthat of communications of said digital content signal between saidreceiver and said module.
 8. The content signal receiver according toclaim 6, wherein said receiver further comprises a means for extractingdata packets related to a single program, and said interfacing meansoutputs said extracted data packets to said module.
 9. The contentsignal receiver according to claim 8, wherein said receiver furthercomprises a first means for processing, said module further comprises asecond means for processing, and communications between said first andsecond means for processing are in accordance with a protocol that isdifferent from that of communications of said digital content signalbetween said receiver and said module.
 10. A descrambling moduleattachable to a content signal receiver, said descrambling modulecomprising: an interfacing means for inputting a scrambled contentsignal from the receiver; a means for descrambling said inputtedscrambled digital content signal; and a means for encrypting saiddescrambled digital content signal and for outputting said encrypteddescrambled digital content signal to the receiver through saidinterface; wherein said interfacing means is configured to input datapackets extracted by the receiver and relating to a single program, andsaid means for descrambling descrambles said inputted data packets. 11.The descrambling module according to claim 10, wherein the receiverincludes a first means for processing, said module further comprising asecond means for processing, wherein communications between said firstand second means for processing are in accordance with a protocol thatis different from that of communications of said digital content signalbetween the receiver and said module.